Compounded mineral oil



metr cal-"eh. 24,1942

COMPOUNDED MIN RAL on.

James 0. Clayton, Bruce B. Farrington, and Robi ert L. Humphreys, Berkeley. Calif., asslgnors to. Standard Oil Company of California, San Francisco, Calif av corporation of Delaware N s. Application November 26, 1938, swarm. 242,560 a J 14 Claims. (01. 252-53) This invention relates to a, new, and useful composition of matter and involves a composition comprising a hydrocarbon oil and an oil-soluble compound of phosphorus containing an. organic radical directly attached to the phosphorus atom by an acyclic carbon to-phosphorus bond. More specifically, the invention relates to compounded lubricants. containing phosphines, phosphinites,

' phosphonites and the like compounds.

The production of improved viscous hydrocarbon oils and particularly of lubricating oils hav ing desired characteristics has been the subject of extensive research and investigation in recent years. Generally-speaking, the compounding of hydrocarbon oils to obtain desired characteristics involves'empirical phenomena, and thenction of untested types of compounding agents cannot be predicted. I

Characteristics which have been the subject of extensive investigation include film strength, the reduction of friction, the' reduction of wear by the addition of compounding agents to inineraL lubricating oils and the discovery of addition agents which will impart the above or other desired characteristics to lubricants without also introducing undesirable properties such as increased discoloration, gumming', instability to heat or oxidation, and corrosivity to modern bearing metals of the copper-lead, cadmiumsilver or analogous types. It is quite difficult to, find addition agents which will give the desired improved properties without also introducing at least one or more of the above mentioned undesired characteristics. 1

, or preferably where R is selected from the group consisting of alkyl, aryl, alkaryl, aralkyl, cyclic non-benzenoid or heterocyclic radicals and in which the remaining. phosphorus bonds are acyclic, produces a composition having unusual and improved properties. carbon-to-phosphorus bond are used herein to The terms acyclic group or acyclic bound to carbon, by acyclic bonds only and in which the phosphorus is not present in a heterocyclic ring. In the above type formula the remaining phosphorus bonds is intended to designate the phosphorusbonds in the formula on which no attached radical is shown.

In particular it has been discovered that friction and wear may be reduced in lubricating oils by addition of compounds of the above type which also serve to maintain the heat stability or the compounded lubricant.' In general these compounds do not decrease the heat stability of the lubricant and have been found not to increase the corrosivity of the oil inordinately. Various of the compounds of this type effect substantially no increased corrosivity in the compounded lubricants under conditions ordinarily encountered and, so far as heat stability is con-.

phoric acid, ortho-phosphoric acid, meta-phosradical directly attached to the phosphorus atom these esters and the inventors materials.

by an acyclic carbon-to-phosphorus bond as do the compounds of this invention. These esters are not obvious or full equivalents of the com-.

pounds utilized in the present invention.

Phosphines are typical of phosphorus compounds containing an acyclic carbon-to-phosphorus bond and the following data comparing tri-phenyl phosphine, tri-phenyl phosphine sulfide, and tri-phenyl phosphite, an ester of phosphorus acid, establish the non-equivalency of In the tests, four samples of oil were heated in an open beaker for six hours at 350 F. The samples consisted of a 1. Acid teated, Western lubricating oil-(S. A. E.

30 grade).. 2. Ditto, +1% tri-phenyl phosphite.- w 3. Ditto, +1% tri-phenyl phosphine. 1 4. Ditto, +1% tri-phenyl phosphine sulfide. After six hours the glassbeaker containing the tri-phenyl phosphite was coated with a hard, black resinous material, while the others were free of any deposit. The deposition of a black resinous material at high temperatures in lubricating oils is characteristic of all phosphite esters, as indicated by additional tests which need designate compounds in which phosphorus is not be recorded here.

Engine tests have shown a correlation with the above beaker tests in that lubricating oils containing tri-phenyl phosphite cover the hotter parts -of the engine with a similar black deposit and phosphines have been found to be definitely superior to the phosphite esters in this respect.

The preferred species of the invention comprises a mineral lubricating oil containing a phosphine, a phosphinite or a phosphonite. Examples of these compounds are: alkyl phosphines, aryl phosphines, alkaryl phosphines, aralkyl phosphines, cyclo-alkyl phosphines, alkyl phosphinites, aryl phosphinites, alkaryl phosphinites,.

aralkyl phosphinites, cyclo-alkyl phosphinites, alkyl phosphonites, aryl phosphonites, alkaryl phosphonites, aralkyl phosphonites, and cycloalkyl phosphonites. I

The broader aspects of the invention embrace compounds of pentavalent phosphorus in which one or more organic radicals is directly attached to the phosphorus atom by acyclic carbon-tophosphorus bonds only. Compounds of this type.

are phosphinates, 'phosphonat'es, phosphine oxides, phosphine sulfides, phosphine selenides and phosphine tellurides. The above compounds contain one of the following groups:

and

respectively, fall within the broader scope of the invention. In the above type formulae the free valences of the phosphorus atom, where shown, should be acyclic bonds and may be linked to hydrogen atoms or a radical selected from the group consisting of alkyl, aryl, alkaryl, aralkvl, cyclic non-benzenoid, alkoxy, aryl-oxy, aralkoxy, alkaryl-oxy, cyclo-alkoxy and analogous radicals.

The compounds of this invention may be prepared by known types of reaction. For example, the aryl phosphines may be prepared by reacting an aromatic hydrocarbon with phosphorus trichloride. The reaction progresses according to the following equations:

Similarly, the phosphonite may be obtained by reacting the phosphonous chloride obtained in Equation 1 with a phenol or alcohol. Thereac tion occurring may be represented as follows:

I on

ItlClz+2ltOli -o RI +2110! on" Likewise, the phosphinlte is obtained by reacting the phosphinous chloride with a phenol or alcohol according to the reaction:

The phosphonous or phosphinous chlorides may be prepared according to Reactions 1 and 2 byrefluxing an aromatic hydrocarbon and phosphorus trichloride in the presence of, aluminum chloride.

Specific compounds particularly suited for addition to lubricating oils to improve the effects thereof according to the present invention comprise: diphenyl phenyl phosphonite,

triphenyl phosphine,

triphenyl phosphine sulfide,

phenyl diphenyl phosphinite,

and phenyl diphenyl phosphinate,

Additional advantages of the new compositions of matter here involved are illustrated by the following test data on lubricating oils contain ing various of the compounds.

In a kinetic oiliness testing machine (described section 3,page 60, of A. P.I. Proceedings, mid-year 1932, published by American Petroleum Institute) under test conditions involving a speed of 5 ft. per minute, a temperature of F. and 1500 lbs. per sq. in load, steel on bronze, 1% diphenyl phenyl phosphonite improved friction reducing qualities of a lubricant 51%. In a. similar test 1% triphenyl phosphine ina lubricating oil decreased the wear 30% and improved friction reducing qualities 10.5%.

In a Weeks'testing machine (similar to Timken machine describedin the S. A. E. Journal, volume 20, page 53, 1932) using Timken cups and blocks operated at a speed of 600 R. P. M. and a loading rate of 40 lbs. per 30 seconds, an S. A. E. 30 lubricating oil I gave a film strength of 160 lbs., where the same oil plus 1% diphenyl phenyl phosphonite gave 720 lbs. In the same test, the lubricating oil containing /2% triphenyl phosphine gave a film strength of 320 lbs., and the oil plus 1% triphenyl phosphlne a film strength of 800 lbs. These-film strengths were measured in terms of load at failure and, although properly comparative, do not represent pressure in lbs. per sq. in. which would be many times greater.

The non-equivalency of the compounds here involved and compounds of phosphorus which do not contain an acyclic carbon-to-phosphorus bond is further illustrated by the fact that in the Weeks testing machine, and under the above test conditions 1% tricresyl phosphate in lubricating oil gave a film strength of only 266 lbs., 1% lauryl phosphate 200 lbs. and 1% phosphatized' castor oil only 320 lbs. as compared with 720 and 800 lbs. film strength obtained with 1% diphenyl 'phenyl phosphonite and 1% triphenyl phosphine, respectively, in the same type of luk bricating oil.

The phosphorus compounds of this invention maybe added to mineral oils containing other compounding ingredients, such as pour point depressors, corrosion inhibitors; compounds for enhancing the viscosity index of the oil, compounds for increasing the stability of the oil at high temperatures and/or for inhibiting piston ring sticking, etc. The invention in its broader aspects embraces mineral hydrocarbon oils in which a soap type of compounding agent, such as a metal naphthenate, stearate,'pheny1 stearate, metal salts of chlorinated fatty acids and the like, may

" be incorporated together with the phosphorus compounds herein disclosed. I

The proportion of the phosphorus compounds of this invention which may be added to hydro- -carbon 'oils may be varied depending upon the type or magnitude of-efiect desired. In general,- small proportions, for example from 0.1% to and preferably from approximately 0.5% to 2%,

are preferred. However, concentrates containing as much as 50% or more of various of the phosphorus compounds may be prepared. Such concentrated solutions in hydrocarbon oils comprise a convenient method of handling the compounds and form a suitable addition agent for lubricating oils and the like. Although hydrocarbon oils such as mineral lubricating oils comprise a preferred species of solvent for the preparation of these We claim:

1. A new composition of matter comprising a hydrocarbon oilfcontaining dissolved therein a phosphonite.

2. A composition as defined in claim 1, in which the phosphonite is an aryl phosphonite.

3. A composition as defined in claim 1, in which the phosphonite is an alkyl phosphonite.

4. A lubricating composition comprising a mineral lubricating oil containing a small amount 7 of a phosphonite dissolved therein.

formulae 5. Acompounded lubricating oil comprising a mineral lubricating oil and a small amount of an organic phosphorus compound having the general formula:

(R')P(XR")b in which R and R" represent members selected 'from the group consisting of alkyl, aryl, alkaryl,

and aralkyl groups; X is an element selected from the group consisting of oxygen and sulfur; a and b are integers selected from the group of numbers consisting of 1 and 2; and in which a+b is always equal to 3.

6. A compounded lubricating oil comprising a mineral lubricating oil and from approximately 0.1% to approximately 10% by weight based on the oil of an organic phosphorus compound having the general formula:

and

' I (XR)u in which R' and R" represent members selected from the group consisting of alkyl, aryl, alkaryl, and aralkyl groups; Z is an element selected from the group consisting of oxygen, sulfur, and selenium; X is an element selected from the group consisting of oxygen and sulfur; a. and b are integers selected from the group of numbers consisting of 1 and 2; and in which a+b is always equal to 3.

8. A compounded lubricating oil comprising a mineral lubricating oil and from approximately 0.1% to approximately 10% by weight based on the oil of an organic phosphorus compound selected from the group consisting of compounds having the general formulae:

(R') a-P(XR") b and consisting of 1 and 2; and in which a+b is always equal to 3.

,9. A compounded lubricating oil comprising a mineral lubricating oil and a small amount of an organic phosphorus compound having the general formula:

in which R and R" represent members selected from the group consisting of alkyl, aryl, alkaryl, aralkyl, cyclic non-benzenoid and heterocyclic radicals; X is an element selected from the group consisting of oxygen and sulfur; a and b are integers selected from the group of numbers consisting of l and 2; and in which a+b is always equal to 3.

10. A compounded lubricating oil comprising a mineral lubricating oil and from approximately 0.1% to approximately by weight based on the oil of an organic phosphorus compoundhaving the general formula:

in which R and R" represent members selected from the group consisting of alkyl, aryl, alkaryl, aralkyl, cyclic non-benzenoid and heterocyclic radicals; X is an element selected from the group consisting of oxygen and sulfur; a and b are integers selected from the group of numbers consisting of l and 2; and in which a+b is always equal to 3.

11. A compounded lubricating oil comprising a mineral lubricating oil and a small amount of an organic phosphorus compound selected from the group consisting of compounds having the general formulae:

(R')P(XR")b and in which R and R" represent members selected from the group consisting of alkyl, aryl, alkaryl,

. aralkyl, cyclic non-benzenoid and heterocyclic radicals; Z is selected from the group consisting of oxygen, sulfur, selenium and tellurium; X is an element selected from the group consisting of oxygen and sulfur; a and b are integers selected from the group of numbers consisting of 1 and 2; and in which a+b is always equal to 3.

12. A compounded lubricating oil comprising a mineral lubricating oil and from approximately 0.1 to approximately 10% by weight based on the oil of an organic phosphorus compound selected from the group consisting of compounds having the general formulae:

' in which R and R represent members selected from the group consisting of alkyl, aryl, alkaryl, aralkyl, cyclic non-benzenoid and heterocyclic radicals; Z is an element selected from the group consisting of oxygen, sulfur, selenium and tellurium; X is an element selected from the group consisting of oxygen and sulfur; a and b are integers selected from the group of numbers consisting of l and 2; and in which a+b is always 

